ci: check public headers conform to c++ ISO standards #4137

Job	Run time
Build mlibc (x86_64, mlibc, gcc)	1s
Compile sysdeps (dripos)	4m 34s
Build mlibc (x86_64, mlibc-static, gcc)	1s
Build mlibc (x86_64, mlibc-shared, gcc)	1s
Compile sysdeps (lemon)	2m 18s
Build mlibc (x86_64, mlibc-ansi-only, gcc)	1s
Compile sysdeps (aero)	5m 17s
Build mlibc (x86_64, mlibc-headers-only, gcc)	1s
Compile sysdeps (ironclad)	2m 14s
Build mlibc (riscv64, mlibc, gcc)	2m 14s
Compile sysdeps (lyre)	2m 17s
Build mlibc (riscv64, mlibc-static, gcc)	1s
Compile sysdeps (keyronex)	2m 23s
Build mlibc (riscv64, mlibc-shared, gcc)	1s
Compile sysdeps (managarm)	2m 33s
Build mlibc (riscv64, mlibc-ansi-only, gcc)	1s
Compile sysdeps (vinix)	4m 32s
Build mlibc (riscv64, mlibc-headers-only, gcc)	1m 57s
Compile sysdeps (astral)	4m 38s
Build mlibc (aarch64, mlibc, gcc)	4m 5s
Build mlibc (aarch64, mlibc-static, gcc)	3m 11s
Build mlibc (aarch64, mlibc-shared, gcc)	3m 24s
Build mlibc (aarch64, mlibc-ansi-only, gcc)	6m 1s
Build mlibc (aarch64, mlibc-headers-only, gcc)	5m 57s
Build mlibc (x86, mlibc, gcc)	1s
Build mlibc (x86, mlibc-static, gcc)	1s
Build mlibc (x86, mlibc-shared, gcc)	1s
Build mlibc (x86, mlibc-ansi-only, gcc)	1s
Build mlibc (x86, mlibc-headers-only, gcc)	1s
Build mlibc (m68k, mlibc, gcc)	5m 34s
Build mlibc (m68k, mlibc-static, gcc)	2m 38s
Build mlibc (m68k, mlibc-shared, gcc)	4m 14s
Build mlibc (m68k, mlibc-ansi-only, gcc)	5m 33s
Build mlibc (m68k, mlibc-headers-only, gcc)	5m 26s
Build mlibc (x86_64, mlibc, clang)	1s
	1h 21m 14s

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